Integrated Crop Management News

Links to these articles are strongly encouraged. Articles may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If articles are used in any other manner, permission from the author is required.

Estimating Nitrogen Losses

June 11, 2008

By John Sawyer, Department of Agronomy

One method to judge nitrogen (N) loss is to calculate an estimate. Predicting the exact amount is quite difficult as many factors affect losses. However, estimates can provide guidance for supplemental N applications.

Rainfall has Affected Hay and Hay-Crop Silage Harvest

June 10, 2008

By Stephen K. Barnhart, Department of Agronomy

Hay is an agricultural product that varies greatly in nutritional quality. The ‘hay market’ frequently uses descriptive terms like ‘dairy quality,, ‘beef-cow quality’ or more quantitative terms like ‘premium,’ ‘good’, and ‘fair’; which have some forage testing guidelines to place hay lots in these categories.

Nitrogen Loss – How Does it Happen?

June 10, 2008

By John Sawyer, Department of Agronomy

Much of Iowa is experiencing excessively wet conditions this spring. With the continued large rainfalls and flooding conditions, nitrogen (N) loss is an issue. While the wet period early this spring had an influence on N in the soil, excessively wet conditions now are especially critical for N losses due to warm soils and considerable conversion of applied fertilizer and manure N to nitrate.

Summer Flooding of Hay Fields and Pastures

June 10, 2008

By Stephen K. Barnhart, Department of Agronomy

Most forage crops perform best when soils have adequate, but not excessive, soil moisture. Standing water, flowing water and waterlogged soils following heavy summer rainstorms or extended periods of higher than normal rainfall patterns can all cause management concerns for forage crops.

Management Suggestions

Economic Impact of Delayed and Prevented Planting

June 10, 2008

By William Edwards, Department of Economics

Most crop producers know that to achieve optimum yields it is important to plant early. However, in years like this when cold weather or frequent rains prevented tillage and planting from being completed, some adjustments may be made to the amount of coverage provided by Multiple Peril Crop Insurance (MPCI) as well as other types of crop insurance. These adjustments are subject to revision each year by the Risk Management Agency and crop insurance vendors.

SCN Confirmed for First Time in Lyon County

June 10, 2008
Map of Iowa indicating the years the counties were infested with SCN

By Greg Tylka, Department of Plant Pathology

Research and extension personnel in Iowa have tracked soybean cyst nematode (SCN) infestations by county since initial discovery of the nematode in Winnebago County in 1978.

Stalk Borers Set to Invade Border Rows

June 9, 2008
Image of stalk borer damage to border rows

By Marlin Rice and Rich Pope, Department of Entomology

Stalk borers are notorious for killing or stunting corn rows next to fences, grassed waterways and conservation terraces. To stop this damage, fields must be scouted and an insecticide applied on a timely basis before the larvae have an opportunity to tunnel into the growing point of the young plants.

June is Bustin' Out All Over!

June 9, 2008
Image of base 50 degree F degree days in regions of Iowa from May 1 to June 8, 2008

And then it rained, and rained some more. Heavy and severe thunderstorms were generated by a lingering front that parked over Iowa for the bulk of the week. Consequently, little field work was accomplished in most fields in Iowa.

Assessing Hail Injury in Corn

June 7, 2008
image of hail damage on corn at the sixth leaf stage

By Roger Elmore and Lori Abendroth, Department of Agronomy

Storms on June 4 and 5 not only brought more ‘unwelcomed’ rain but also damaging winds and destructive hail. Variation currently exists in corn development across Iowa, ranging from emerged to the sixth leaf stage. Vegetative stages are determined and most often referred to based on the leaf-collar method developed by Iowa State agronomists.